Generally, meat or fruit pierogi are boiled till they float. Fruit serves well with a bit of sour cream sweetened with sugar. Potato and Sauerkraut fillings get pan fried and served with your choice (this is a regional preference) of butter, diced bacon or onions.

I love the mushroom filled perogies. There's a lady who makes & sells them at the farmers' market in Missoula, but I think she steams them instead of actually boiling; they are incredibly tasty! She also makes blueberry filled & serves them up with a bit of yogurt. Now I'm hungry for perogie.
Oh BTW, there's all kinds of perogie dough & filling recipes online for those who want them.
Regards, GF.

The man who intoxicates himself on bad whisky is sometimes moved to kill his wife and set his house on fire, but the victim of applejack is capable of blowing up a whole town with dynamite and of reciting original poetry to every surviving inhabitant.

What's great about the pot cheese variety is the filling is so easy to make. After squeezing out the whey you can reboil it (the whey) and make homemade riccotta. By far the best return on investment for a gallon of whole milk.

__________________
See, that's where the real story is.
In the competition for the attention of the space aliens.
Everyone's equal in the eyes of God, but the space aliens, you've got to figure they would play favorites.

There's a good episode of Three Sheets where they visit Poland and crash a wedding. They soon realize the danger when baskets filled with bottles of vodka arrive and the feats of strength contests start. No good can come after a couple of bottles and axes start to get thrown around. Aaah childhood memories.